text:
Can airlines schedule more flight arrivals than the destination airport capacity?
Takeoff and landing efficiency at an airport seems to depend on a number of factors, like number of runways and gates, infrastructure maintenance, weather, or even notorious traffic congestion in some areas.

Busy approach at Heathrow, Youtube
Is there some process to prevent airlines to schedule more flights than the destination airport capacity? e.g. some coordination between ATC, airlines, and airports management. If so, how are airlines requests handled, is there some rule for fair sharing of the most demanded time slots?

Short answer: it depends on airlines bargain power. In US it is quite common but not possible in rest of the world.

Since the other answers focus on the US and you specifically mentioned London Heathrow, I will answer for Europe.
In Europe, Eurocontrol uses a central Air Traffic Flow Management (ATFM) system to avoid both congestion at the destination airport and in the enroute environment.

The Air Traffic Flow Management System of the European Region comprises two Central Management Units, specifically the EUROCONTROL Central Flow Management Unit and the International Air Navigation Service “East”, which are supported by Flow Management Positions in local air traffic control units.

(Eurocontrol ATM Lexicon ATFM System of the European Region)
In practice this works by assigning departure slots to aircraft when they are still on the ground at their departure airport. This way, longer holding times at the destination airport can usually be avoided, which both increases safety and reduces fuel burn.

ATFM departure slots are allocated centrally by the European Network Manager upon the request of the local Flow Management Position (FMP), when an imbalance between demand and capacity is foreseen at airports and/or en-route. The purpose of such regulation is to hold aircraft on the ground.
An ATFM slot tolerance window is available to ATC to sequence departures. The standard slot tolerance window is [-5 minutes, +10 minutes]. ATC at the departure airport has a joint responsibility with aircraft operators to ensure that flights departure within the allocated ATFM slot tolerance window in order to optimise traffic flow.

(Eurocontrol ATFM Slot Adherence)
The pilots will receive a Calculated Take-Off Time (CTOT) when such a slot is assigned:

A time calculated and issued by the Central Flow Management unit, as a result of tactical slot allocation, at which a flight is expected to become airborne.

An Air Traffic Flow & Capacity Management (ATFCM) departure slot, forming part of an Air Traffic Control (ATC) clearance, which is issued to a flight affected by Network Management regulations. It is defined by a time and tolerance (-5 to +10 minutes) during which period the flight is expected to take-off.

(Eurocontrol ATM Lexicon Calculated Take-Off Time)
In general, this system works quite well. In July 2019, ATFM Airport delays only contributed 1 minute of delay per flight on average:

(Eurocontrol - All-causes delay to air transport in Europe for July 2019)
To actually answer your question: Yes, airlines can schedule as many flights as they want (unless the airport is an IATA Level 3 Airport), but flights will not be allowed to depart on time if the capacity is not available at that time. It is therefore in the airline's economic interest to schedule flights accordingly.
See also:

How is Calculated TakeOff Time (CTOT) calculated?
What is the difference between en-route delays and airport delays?

Good addition, can we assume slots are allocated this way essentially or only to IATA level 3 airports? even if IATA and Eurocontrol are two different organizations.

The slots you mention in the linked question are different to the ones I talk about here. Those slots are airport slots given out by the respective airport authority. E.g. airlines will have to purchase such a slot when they intend to operate to/from Heathrow. But every controlled flight in Eurocontrol airspace is under ATFM control and will (if necessary) be delayed with a CTOT, not just because of possible airport delays (see "ATFM En Route" and "ATFM Weather" in the chart I show).

I'll answer for the US. As long as there's no official slot program, airlines can schedule however much they want to an airport, beyond what it should be capable of handling.
Now that doesn't mean ATC lets a free-for all happen. Hopefully, various traffic management units are on it and aware of how much demand is scheduled and already airborne into the airport/region/area that there's too much demand, and will implement various flow control programs to moderate the volume to what can be accepted into a specific sector(Certain airways can get super busy and require these types of actions), or airport. These control programs will either slow aircraft farther out from their destination, hold, or give small to longer delays on the ground, depending on how over scheduled or limitations of weather at the destination.
[Begin edit poriton]
Since the other part of the question wasn't there when I first answered, I'll answer now.
Slot controls vary heavily from airport to airport. In the US, LGA, LGB, DCA, SNA, and at times JFK are slot controlled, with a few others threatened to go to slots due to how many delays they impact the system(SFO, EWR, and ORD). How each airport deals with the slot allocation is different due to how they got slot controls. DCA is controlled partly through congress, LGA and SNA are restricted due to noise controls. In the US, once an airline gets a slot, often times it's considered transferable property, so airlines can sell them to each other if needed.
Now if a slot isn't used and goes back to the airport, the airport can put it up for bid, or allow applications for it, again depending on how their program is structured. AT DCA, some slots are transferable, some require an act of congress to change or modify, and some can only be used for certain routes or types of cities.

May be similar in Europe. Recently, due to construction work in Brussels, my flight BRU-PRG was 2 hours delayed. It actually was delayed on the previous leg PRG-BRU; people were sitting in the plane and waiting to take off, but the plane did not receive a flight plan confirmation -- the traffic control simply didn't let the plane take off because it couldn't land.

Yes, in the U.S. each metered airport (major airport) has what we call an AAR (Arrival Acceptance Rate) which varies sometimes hourly depending on weather and runways in use. One day the scheduled flights might get in with no delays, and the next many could be delayed by hours if the AAR goes down. This is managed by our flow control system which takes the current AAR for each airport and looks at pending departures for that airport and spaces out the departure times so that the AAR isn't exceeded. We call this the "EDCT" time (expected departure clearance time) and it shows up on the flight strip for ATC and is sent to the airline's dispatch office. A flight might be scheduled to depart at 12 noon, but their EDCT time might be 12:37 and they're supposed to plan their pushback and taxi so they're "wheels up" at that time.
You can see the standard AAR's at http://www.fly.faa.gov/ois/ (click on east or west directory, then the appropriate Center and airport). LAX for example in VMC conditions using 25L/24L and R for approach has a 74 aircraft-per-hour AAR, but if it's foggy (low IMC) and they're using only 25L and 24R, the AAR drops to 58 per hour. If 70 are scheduled to arrive in some given hour, on a first-come-first-serve basis the computer will put out EDCT times to spread them out so only a max 58 will arrive in that hour, and the rest get bumped out to the next (and on and on).

For any Airport, if the demand is more than the capacity.Then those airports are categorized as Level 3 airports for which Slot Coordination is a must.
Ex: -
For these kind of airports, If an Airline wants to operate in Summer S17, then Airline should be having grand father rights which is gained by operating in Summer S16. And yes, if there is any remaining or empty slot, any airline can apply for it. It is a very trasparent process.
In these kind of airports, if the airline is misuinng the slot then there is huge penalty to be paid and also very good chances of loosing the grand father rights.

This answer sounds very specific to a certain country or area. Please include in the answer where it applies.


text:
Does angle of attack affect affect load factor?
I have been reading FAA Part 23 recently, and I have some confusion regarding the flight envelope of an aircraft. In some references, the maneuvering speed of an aircraft is written as follows:

It says that the lift produced is equal to weight times the maximum positive load factor. When defining the load factor, some references quote that it is simply the acceleration the aircraft is experiencing, and some more references quote that it is simply the lift divided by the weight of the aircraft. After further reading, I have found that you can find this load factor by considering the force body diagram during a steady level turn. Let us set the AoA as alpha, roll angle as phi, and also consider that the wind x axis coincides with the local horizon x axis. When I formulate the force equilibrium of the aircraft with respect to the local horizon axes, I get the following equations:

If I multiply the former with sin(phi) and the latter with cos(phi), and substract the former with the latter, I get:

With n equal to 1/cos(phi) according to some references
That is still fine since it match the reference that I read. But my problem starts when I substitute n = 1/cos(phi) to the force equilibrium equation on the z axis, I get:

If we see the equation above, it doesn't match the lift used when calculating the maneuvering speed, nor does it match the definition of load factor equals L/W. After looking at the equation repeatedly, I conclude that the equation would match the definition of load factor that I have read if the AoA is zero. However, I then realize that the lift coefficient used is the maximum lift coefficient which certainly happens when the AoA is not zero. I'm still having trouble understanding this specific topic, I would really appreciate if someone can clarify this to me.
Thanks in advance

I think you can safely ignore the T sin \alpha term because T is already much smaller than W for most aircraft and sin \alpha is close to 0.

Ahh i see, i didnt realize that, when i took an example, i found that the offset is only 3% when i neglect the Tsin(alpha) term, im very grateful now it has been cleared, thank you

Generally, when determining maneuvering speed,, you are interested in the maximum allowable load factor, or the Placard G-Limit. defined by the aircraft manufacturer. This does not change as AOA changes. It is based on the structural G-Limit, which is the aircraft G loading at which some part of the aircraft structure will fail, and that can change as a result of gross weight, aircraft configuration, external stores, etc. Maneuvering speed is that minimum airspeed at which the aircraft is capable of establishing a G- Load (Load factor) equal to the placard G-Limit.

Yes angle of attack affects load factor! With a load factor > 1 during manoeuvres, a higher angle of attack allows the C$_L$ to be high enough to create the extra lift. At an AoA of zero there is very little lift created.
Usually, thrust is not considered in the gravity axis. In jet the L/D > 10, $\alpha$ < 15°, so disregarding the vertical component of thrust yields an error of 3% or so.

A dissection of the given formula yields the familiar lift equation:
L = Density × Area × Coefficient of Lift × V$^2$
L = Weight × max load factor (placarded + and - in G)
Angle of attack at Clift max would be the stall AOA, where coefficient of lift is greatest.
Using the placarded G forces as a limit, one can see that below a certain V, AoA will exceed stall angle before the G limit is reached.  This is why one can manuever at lower speeds without overly stressing the airframe, but one must be careful not to stall the aircraft.
Above this "manuevering speed", an AoA less than stall is sufficient to produce enough G forces to exceed the G limit.
AoA is built into coefficient of lift in a generally linear manner.  Actual data for the airfoil of your aircraft (coefficient of lift vs AoA and stall AoA) is available at airfoiltools.  The load limits and manuvering speeds should be in the POH manual of your aircraft.

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text:
What does happen when a supersonic aircraft passes another supersonic aircraft, regarding sonic booms?
I wonder about sonic boom existence and effects when two fast aircraft interact, for example:

When supersonic aircraft flying opposite routes cross each other, do pilots hear a sonic boom?
If they fly in the same direction, with the appropriate offset, does one hear a permanent sonic boom?
If two aircraft fly in opposite directions at Mach 0.6, can they create a sonic boom by adding their individual shockwave speeds?

Two Sukhoi Su-30MKI maneuvering, Wikipedia
Further than the sound aspect:

What are the effects on the aircraft?
Is there a distance after which the effects become insignificant?

When supersonic aircraft flying opposite routes cross each other, do pilots hear a sonic boom?

If the aircraft are near enough, yes.

If they fly in the same direction, with the appropriate offset, does one hear a permanent sonic boom?

The boom will not be permanent i.e. static, but yes, it will be persistent. However, it should be noted that the shocks from various parts of the aircraft body will interact nonlinearly (mostly coalsce), resulting in unpredictable results.

If two aircraft fly in opposite directions at Mach 0.6, can they create a sonic boom by adding their individual shockwave speeds?

No, sonic boom is caused by the object travelling faster than sound while the disturbances travel in the medium with speed of sound and get 'bunched up'. So, the aircraft has to fly supersonic with respect to the medium

What are the effects on the aircraft?

Shock wave is basically a pressure discontinuity. So the effect will be similar to that of an impact, whose strength depends on the shock wave.

Is there a distance after which the effects become insignificant?

Yes, but it depends on the aircraft size and the speed. The shock wave produced by the bullet loses its strength in a short distance, while the Concorde has to be flown over sea and Tu-144 at over 35000' to mitigate the effects.

In the first part of your answer where the a/c are in opp directions it seems to me neither pilot would hear the other. The sonic boom, and all other sound of the a/c follows it. The boom propagates at the SOS, so if the other a/c is going faster it would not catch up to him.

I don't think pilots will hear the shock wave if both aircrafts are at supersonic speed.

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text:
What controls the brightness of the MCDU display and keys?
What brightness does the brt and dim on the right side of the MCDU MENU button change?
The brightness of the display, the keys or of both?
And if only one of them, what controls the other?

(source: skalarki-electronics.eu)
EDIT: As shown in this video, the brigghtness knob turns just the display on/regulates it's brightness.
What changes the brightness of the keys (They seem to be lit befor the MCDU is turned on)?

The brightness of the keys is controlled together with the rest of the pedestal via the "INTEG LT MAIN PNL & PED" knob on the lower pedestal below the capt ACP.

These buttons are to increase and decrease brightness of MCDU. Also, they are used to turn on and off the unit.
As explained here:

BRT AND DIM KEYS
  Control the light intensity of the entire MCDU. MCDU power up is performed
  with the BRT key and MCDU shut down is performed with the DIM key.

And here:

Repeatedly clicking on the "BRT" (the top of the paddle switch) will
  switch the unit on and increase the brightness. The reverse is also
  true. Repeatedly clicking on the "DIM" (the bottom of the paddle
  switch) will decrease the brightness and switch the unit off.

Is there some sort of warning between the lowest "Dim" setting and "Off"? I can see someone (me in particular - I like my dash display very dim), thinking "that's still too bright, let me hit Dim again" and turning the thing off because it's already at its lowest setting.


text:
Fighter Jets speed
How does an aircraft measures (or calculates) its speed while in air? Which equipment or sensors are used for measurement of speed? Does it takes Earth as a reference frame for its speed measurement so its speed is relative to earth surface OR does it calculate's absolute speed?
Does the aircraft altitude above sea level or ground level effects the measurement of its speed? I mean if the aircraft is flying low vs high then will it use same sensor to measure its speed?

Have you seen these questions/answers: Why are planes slower at higher altitudes? and Why is there a difference between GPS Speed and Indicator speed?

There's no such thing as "absolute speed".

The speed most relevant to flight is airspeed. It is measured by using the aircraft’s pitot-static system. The speed most relevant to navigation is ground speed. It can be calculated from True Airspeed adjusted for airmass movement (wind drift). Or, it can be measured using GPS.
There are 4 types of airspeed, 1 type of relative airspeed, and 1 type of ground speed commonly used in aviation. They are:

Indicated Airspeed - indicated on the instruments
Calibrated Airspeed - IAS adjusted for sensor placement
Equivalent Airspeed - CAS adjusted for air compressibility
True Airspeed - EAS adjusted for density altitude
Mach Number - a ratio of airspeed over speed of sound
Ground Speed - ground position change over time

Absolute Altitude is another commonly used term in aviation. Absolute airspeed is not a commonly used term.


text:
Is it at all possible (or safe) to pursue a pilot's license with a history of mental illness?
I am in my late twenties. To put it bluntly I have a history of mental illness going back to my teens. My quick summary:

Diagnosed with depression and prescribed Wellbutrin in my teens. I discontinued without doctor approval and stopped going to psychiatry.
Diagnosed with ADHD in college and prescribed a litany of drugs to "try" including Adderall, Ritalin and Vyvanse. All were stopped with approval by my doctor because of horrible side effects and lack of any therapeutic effect.
Mid 20s (~1 year ago) had an anxious breakdown due to an online harassment campaign and voluntarily committed to a mental hospital, spent 48 hours there. Left the hospital with an SSRI and Klonopin (benzo) prescription.
Recently I discontinued SSRI use and switched back to Wellbutrin, have not taken Klonopin in 6 months or so but my doctor has had me keep it around in case of panic attacks.

I would say I have my depression under control but I have had 1 panic attack in the past six months.
I have been interested in aviation since I was a child and recently considered the idea of potentially pursuing a PPL, but I'm not hopeful. I'm 100% certain this would not be possible in the near future due to my current medication (Wellbutrin.) My doctor is confident that I can taper off this medication in the next 3 months however, and he views me as more or less stable. I don't feel anxious or depressed anymore and I haven't in some time. I like to think this is all behind me.
Is there any chance of attaining a medical in the far future (maybe 3 years of total stability from now), or is it pretty much not going to happen in this lifetime? Is it even a good idea to attempt to learn to fly, or should I stay far away from an airplane forever given my history?
Thanks for reading.

You've identified, quite rightly, that flying is not on the cards right now. Anything else will require the assessment of an Aviation Medical Examiner. I'd wait until you've been off the drugs for a few months before starting down that track.

One thing I've learned to be always true is that if you're asking yourself whether you should fly or not, the answer should always be no. It could be weather conditions, medical issue, you're not feeling well or simply just tired, if you come to the point where you're asking the question, it's because deep down you know it's not the best idea. Take care of yourself first and then go learn to fly if you get the green light from medical staff. The plane will always be waiting don't worry ^^

In general, I'd repeat this answer, although with the caveat that @CatchAsCatchCan is almost certainly correct that you'll probably be better positioned to start the process when you have 6 or 12 months without meds & without any issues. Best wishes to you!

Surely a simple "No, it's not possible" is much more helpful to the OP here than dreamy I'm-ok-you're-ok discussions?

I have no medical degree, but I can give you some things to consider:
Even as a hobby, flying is at times a high stress environment. You must stay alert at all times, and the ability to maintain functionality even when all hell breaks loose is highly desirable. It's not all clear blue skies and three degrees of freedom. You got checkrides, new things to learn, old things to remember, and pretty much everything you do might end up badly.
You correctly point out that medication that effects cognitive capabilities is a strict no-go. As such, a history of using them might not exclude the possibility of ppl level medical certificate, but would require jumping through some hoops, with no guarantee of succes.
Any history of suicidal tendencies is pretty much a 100% no-go. Just a not, you do not mention this, but I'll let the cat out of the bag anyway.
Your anamnesis has quite a listing of various mental issues. You do realize this is a major obstacle, which is a good start. Loading high expectations on PPL licence would not serve your recovery well, but my non-expert opinion backed up by some real life examples is, that a person can shed even quite severe mental issues, and regain & maintain "full functionality" without any medication.
In your case the minimum requirement would be a long period of stability. Be honest to yourself and do not push it. If you get on top of things naturally, you might be good to go for PPL in some point in future. But do not risk you mental health on it, not but pushing towards it, and not by hanging on to it if you get there. As I wrote in the beginning, flying is a high stress environment at times, and it can trigger all kinds of unexpexted reactions. There is absolutely no loss or shame in putting the safety of yourself and the others above your dreams.
Flying is so much fun it's hard to describe it, but there are many other things just as fun, even more so.
Dream big, but don't let your dreams run you, or they will ruin you.

"Any history of suicidal tendencies is pretty much a 100% no-go." okay

Yes @Abdullah, does that not compute? You must remember that there are no absolutes.

If you can convince both the AME and the FAA (by way of convincing at least one psychologist) that your history with suicide is completely in the past, you can get your medical back.  Takes a while.

Hence the "pretty much". It's not 100%, but close.

You don’t say where you are, so I’ll answer for the US. If you’re somewhere else, the answer may or may not be similar.
The FAA has a dim view of mental health issues requiring any medication. They are rightly concerned about the issue being treated and what may happen if you stop taking the drugs, and they’re also concerned about the possible side effects, which are often worse than the condition being treated. It does not matter whether you are experiencing those side effects, just that they are possible.
In general, for any mental health issue, they’re going to want a letter from the treating doctor saying that you have been off all medication for at least six months and remain stable.
That said, the FAA has actually approved a few such drugs; maybe yours is one of them, or maybe your primary doctor can switch you to one that is and see if it works well enough. I suggest you book an “eval” appointment with an AME near you, explain the details, and see what options you have.

Other answers have given you a flat statement about how this applies to a PPL. I'm going to slightly frame-challenge your question though.
Why are you looking at a PPL as the only type of aviation?
I used to fly hang-gliders. Learning to fly hang-gliders and paragliders does require some minimum physical fitness, and for you to be mentally able to learn the movements, but this is all. And once you've learnt to fly, a powered hang-glider or paramotor rig can fairly easily be added.
Or going up a step from there, weight-shift microlights (up to a certain maximum weight) do not require a PPL either.
Gliders may need a PPL, depending on where you are.  This may not require a formal medical though.
All the above give you routes into aviation which do not require a third party to check your medical history and authorise you to fly.  However in all the above cases, and any other skill-based sport (such as scuba diving or climbing), you are required to self-certify that you have no issues which would interfere with your ability to carry out the sport.  If you suffer from panic attacks, you cannot truthfully say that this is the case.  (Thanks to StephenS for this addition.)
I do concur with other posters that any form of aviation can be a high-stress activity at times. If stress triggers panic attacks, this will become highly dangerous.  You should also be aware that it can sometimes take a little while to build your skills; and you should be aware that simple misjudgements happen and you're sometimes going to have a bad landing. If you're likely to regard these as failures of you as a person, instead of just as mistakes which happen, this may not work well with depression.

@Jpe61 It's certainly not cheap compared to something like mountain biking! :)  But like you say, it's a damn sight cheaper than a PPL.

Gliders require a PPL in the US. You don’t need a medical, but you do have to sign a sworn statement that you’re not aware of any medical condition that would make flying unsafe, which the OP can’t do truthfully.

I speak not as a medic but as someone who has a history of depression.

One thing to consider is, do you drive? Have you ever had to pull to the side of the road as the result of a panic attack? You can't pull over when you're flying a plane.

Did you ever run into the back of the car in front when it stopped unexpectedly at a junction? Was it because your thoughts were taken up with stress or worry? (I did this once)

Every kind of drug for mental health problems is likely to slow your reactions.

You will have to spend many hours in a small cockpit with an instructor. They may  be very uncomfortable if they know you are subject to panic attacks. Some may not mind!

You owe it to yourself and everyone else to be certain the problems are behind you. I know from personal experience how easy it is to think one day, "I feel wonderful! I'm cured!" and to stop taking the meds only to have a relapse weeks or months later.
What to do
If you are really serious you should be able to go without meds safely for at least a year.
You may be able to get a trial flight as a passenger where the instructor lets you take over the controls briefly. You may find that the noise and sense of disorientation, not to mention airsickness, isn't the fun you thought it would be. Some people have one flight and that's enough.
Be aware that you will have to have a medical exam before being allowed to take lessons. They may check your medical history. Look up the regulations in your local area - they will probably be on the flying school's website. If in doubt and you don't want to prejudice people against you, you can  phone a school where you aren't going to fly and make enquiries about how all the medical stuff works. You should be able to chat to a medical examiner.
EDIT See important comment by @Ralph J below. Check all of this out before committing to spending a lot of money.
If you are still serious then  wait that year.
In the meantime learn as much as you can.  Get a realistic flight simulator for your PC and learn all about the different instruments and controls. Focus on simulated planes that are used for tuition at your local flying school.
Study and take the theory exams!
Become an expert at everything except the real thing.
If after a year you have been episode free and meds free then you can consider taking proper lessons.
Good luck. I know from my own experience what you are going through. I also believe that most of life's problems can be overcome with determination.

Nice answer.  I would say that being off meds is not necessarily required though - what's required is for you to be stable with whatever your current treatment plan is.  Some mental health conditions can only be treated with meds, and there's no shame in that.  So I wouldn't say have a year without meds, but rather have a year without any change required to whatever meds (if any) may be involved, and without any incidents requiring external assistance such as panic attacks.

@Graham - I agree provided that the meds are known not to reduce reaction time or alertness.

In the U.S. at least, they will check your medical history because you're required to provide it. It's a serious criminal offense to omit any element of it from the FAA's form. So the OP needs to understand up front that the medical history will be reviewed before the FAA medical will be issued. One can do some training (ground school, some flights with an instructor) before the medical is issued, but if you're going to spend the $$ to start down that path, you want to know up front if you'll be allowed to complete it.


text:
What is the range of pressures a space shuttle can withstand?
Pressures, as on the external surface of the space shuttle. I want to design my own functioning space shuttle (on an extremely fundamental level with consideration of only the external structure, nowhere close to the real thing) and would like to run a wind tunnel test on it, and I wanted to know what pressures a space shuttle can withstand in order to design my own spacecraft to match and potentially exceed those values.
I appreciate any help that anybody can give me, even if it happens to be some advice, constructive criticism, or the answer to my question.

This might be a question for [space.se]

@CatchAsCatchCan They don't allow DIY rocketry. Of course, the problem is solved if the reference to building a spacecraft is deleted.

The Shuttle Crew Operations Manual has basic information which might answer your question. Starting on page 799 (section 4.3) you'll find Airspeed Limitations.
During ascent the dynamic pressure limit is 819 psf. The limit is based on thermal protection constraints, rather than other structural concerns.
During entry, the dynamic pressure limit varies by velocity. The limit is based on stability (controllability) constraints.

During a Return to Launch Site (RTLS) abort, the allowed limits were a bit higher:

Page 1002 has a graph showing typical Ascent dynamic pressure:


text:
Why does the Sukhoi-30 MKI have both canards and conventional horizontal stabilizers?
I believe the Sukhoi-30 actually has 3 means of altering pitch and roll - canards, horizontal stabilizers, and thrust vectoring.

Image courtesy www.mars.slupsk.pl

What is the point of this?
Does it lead to an increase in maneuverability?

A loop-the-loop on the spot would be difficult otherwise.

The loop-the-loop is quite an amazing maneuver. It looks like the perfect move in a dogfight. However, with advanced missile technology, theres very little use for that kind of maneuver.

@MadhavSudarshan Sure. But it means the answer to "Does it lead to an increase in maneuverability?" is a pretty solid "yes".

@MadhavSudarshan Read about the US experience in Vietnam. In the 50s the US decided to remove machine guns from fighter jets because of "advanced missile technology". They learned to their rude surprise that dogfights are still relevant because you can't use missiles effectively at really short range (and enemy pilots are creative enough to get close to you)

Yes, increased maneuverability and redundancy are the main benefits of this layout. Another is a wider possible range of the center of gravity.
In the video linked in Federico's comment you can see that the canards reach high negative deflection angles in high-alfa attitudes: This means they will still operate in attached flow when wing and tail are already fully stalled. A canard-less airplane would only have thrust vectoring for control in this situation. Also noticeable in the video is the negative static stability which becomes evident in the lively elevator movements during the landing approach towards the end of the video. When you need agile pitch controls for artificial stability, it helps to have a second pair of them in highly dynamic maneuvers. The small size of the canards might be misleading: Since they will affect the flow over the inner wing, they are quite effective and powerful control surfaces.
A multirole, long-range aircraft will have to deal with a wide variety of ordnance and fuel loads, so the addition of canards will allow to trim a wider range of c.g. positions. Without them, some load configurations, and consequently some missions, might not be possible.

Be careful of confusing manoevrability and agility. The former describes turn performance (min radius, max sustained turn rate etc), while agility describes how quickly it can change manoeuvre state; depends on stability, handling qualities, control power etc. Given this design is based on a legacy version, the large moments of inertia in pitch demand greater control power to achieve the agility required of modern fighter, especially in the post stall/high AoA regime. Also, as mentioned, better control power at higher AoA facilitates relaxed stability longitudinally, which in turn improves agility and possibly handling qualities, depending on how it is implemented through the flight control system.
In some fighters, one I can think of, differential use of canards can be used to increase directional control power as the pressure differential across the fuselage helps to pull the nose around. This is useful at high AoA where yaw, not roll, is predominant wrt aircraft axes when changing lift vector direction.


text:
Can fighter jets drift on air, and if so what does it look like?
I saw a video of a jet "drifting" from the air. I don't know if it was the quality of the video or my lack of knowledge with maneuvers but it didn't really do much but just fly over but apparently from the comments they were talking about how it was possible for a jet to "drift" from the sky.

By "drifting" do you mean sliding sideways while turning, like drifting a car?

That is a modest example of high angle-of-attack flight.  https://en.wikipedia.org/wiki/Cobra_maneuver

That depends a bit on how you define drifting. I don't think that the definition of motorsport drifting can be applied to a (flying) aircraft. However if you relax the exact definition a bit, you could say that drifting is roughly that your vehicle points (severly) in a different direction then the direction it is travelling. Therefore the vector in which the aircraft points, is (markably) different from its speed vector.l
If you accept this definition, then the answer is: All the time.
A key concept for an aircraft is that of the Angle of attack, which is defined to be the angle between the incoming airflow and the center line of the aircraft. You can see it clearly in this picture (taken from here):
The direction the aircraft travels to is marked by the "Velocity" arrow. The velocity arrow corresponds to the airflow direction. The pitch attitude is the angle between the horizon and the centerline of the aircraft. The angle between these two lines is the Angle of attack, or in other words, the angle of the incoming airflow as seen by the aircraft.
The Angle of attack is the prime contributer to how much lift an aircraft produces. The larger the angle of attack, the more lift it generates (up to approximately 15° at which stall sets in).
Therefore (a bit simplified), because all aircraft require a non-zero angle of attack to fly, they all "drift" through the skies (*1). You actually see that in the video you linked. Because the aircraft turns, it requires more lift (in order to go around the corner), hence more angle of attack which is exactly what you see in the video. Some fighter jets take this to the absolute extreme, by performing maneuvers with very large angle of attacks, for example the cobra maneuver (*2).
(*1) There is a small exception, because some aircraft are designed such that in cruise flight, they fly at a 0° angle of attack, but in this sense that is a sidenote.)
(*2) Perhaps as an additional sidenote: the cobra maneuver is enabled by thrust vector control, a technique with which aerodynamic control losses all meaning for these aircrafts.

Based on the appearance of a "drift" in the automotive world, yes.
There's a long complex answer that suggest this is happening all the time, based on a (IMO) sketchy definition of "drift" -- but if you apply that definition only in the horizontal plane, then yes, many aircraft can "drift".
Correctly, in aviation this is called a "skid" and is considered a hazardous maneuver -- for most aircraft it requires crossed controls (i.e. right rudder offset by left aileron to counter roll coupling due to dihedral) but highly maneuverable aircraft, like many warplanes, have little or no roll coupling to rudder input.  With these, especially at relatively low speed, a large rudder input will result in the aircraft's nose deflecting and remaining deflected for some time before body lift on the fuselage and fin strake(s) (if present) changes the velocity vector to match the new pointing.
That said, with a lot of altitude cushion (to recover from the unpleasantness that can come from a nose-down crossed control situation like a skid) even a Cessna 152 can make a skidding turn with wings level.


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How does a lean die-out occur in a turbine engine?
Essentially a lean die-out occurs at higher altitudes with low engine speed, and low fuel pressure, which results in a weak flame. So an overly lean mixture exists.
With these conditions, how would this exist? Typically at higher altitudes you're assuming there's less air, and with a lower engine speed, you'd get less ram air going into the compressors.

When reducing power, if the fuel flow is reduced too quickly, the ram air blows the flame out of the combustor, the flame dies. The role of the EEC/FADEC is to manage the fuel flow variation in a way which prevents this to occur (source).

Mins, why not just answer the question?

With these conditions, how would this exist?

The comment by @mins appears to answer the question for modern engines, although I'm not quite sure if I'm interpreting your question as you intended, but if your intent is to find out how this happens from an operational standpoint, here's an answer for the P&W JT9D-3 through -7 engines as used on 747-100/200 aircraft. In 10 years of flying with these engines, I only had a flameout once, so it wasn't a major problem, and the -3 engines were more susceptible than the later variants.
The scenario is that you're above 35,000 and you've reached your descent point and need to reduce power from full cruise to idle. We were taught to first lower the nose to ensure that we wouldn't lose any airspeed (a little gain was okay) and then to slowly bring the thrust levers all the way back. As I remember, we typically took at least 5 seconds to get the levers back.
In other words, if you suddenly reduced power or lost airspeed, you risked a flameout.
From the pilot's standpoint, if you had a flameout, all you did was tell the flight engineer to restart it when low enough that that was possible.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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Can different airliners of the same type feel different to a pilot?
(There's a related question Do two of the same model of aircraft feel different to fly? already. But:

It's not about airliners, and most of the answers concern other aircraft.
Not one of the answers discusses feel - subjective experience. They discuss performance, position and orientation of controls, where the air-vents are, the lighting - but not how it feels (or sounds or even smells). I'm concerned with this subjective experience.)

By "different airliners of the same type" I mean examples of exactly the same model in the same configuration with the same engine options.
By "feel" I mean how the aircraft responds and behaves, as experienced subjectively by the pilot.
Given a pair of cars of the same model in the same configuration, after a year or so you might well find that one feels different: the steering in one may be twitchier or looser, the clutch bites differently, the brakes respond sooner, it bounces more excitedly over bumps, the gear lever is stiffer.
There may also be different noises from the suspension, or sound from the engine at idle. Perhaps one car smells different on wet or hot days.
Are similar subjective differences apparent to pilots of different examples of the same airliner?

DeltaLima has posted an answer to the question you reference that addresses airliners.

@PeterKämpf @ koyovis I have excluded exactly those kind of differences ("position and orientation of controls", "performance", both listed in the question as not the kind of difference I am asking about) from the scope of this one. "Difficult lateral trim" is not quite what I want to know about, but it's closest. The analogous examples from driving a car that I gave are an indication of what I mean.

Engines are flat rated exactly to remove differences between aircraft of the same configuration, expect for their tail number. They need to perform predictably as per the flight manual, so the pilot gets no surprises. See: https://aviation.stackexchange.com/questions/46577/why-isn´t-toga-thrust-always-100-n1-or-n2/46612#46612

By "feel" I mean how the aircraft responds and behaves, as experienced subjectively by the pilot.

Yes, there are differences but they are generally small and might not be equally apparent to all pilots. That, of course, is a problem with "subjective differences."
However, I do remember a 747-200 that I flew that did have a distinctive difference from other -200s of the same configuration, and a difference that other pilots noticed.
"...when I pulled the power at 50 feet, the plane sunk like a rock....The captain later apologized for not warning me that this particular airplane (I hadn't been in it before) had a tendency to drop out of the sky when you pulled the power."
The quoted excerpts are from the third paragraph of https://terryliittschwager.com/Journal/1995-07-04.html.

Exactly the kind of thing I was looking for thanks. Do you have any idea why this particular aircraft had this tendency?

@DanieleProcida No, I don't, and it wasn't something that within the context of the company I was flying for would have been pursued. And, once you knew about it, you just planned for it.


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Role of thrust during take off
When a airliner takes off, it looks like after rotation and lift-off, the plane flies up in the air parallel to the length of its fuselage.
Assuming lift from the wings is the major force in taking off, that should not necessarily be the case. (E.g. during landing the fuselage is typical at an angle with the movement of the aircraft.)
So, I am wondering, is my observation wrong (i.e. do airplanes not take off parallel to their major axis)?
Or is the engine thrust a greater factor in taking off, since the thrust vector is by design always parallel to the fuselage.
Or, 3rd option, is the airplane designed such that the lift of the wings in the default take off configuration results in a parallel flight, e.g. because this is most efficient from aerodynamic POV?

Engine thrust a greater factor in take off ... most efficient from
aerodynamic point of view

Aircraft need to overcome drag with thrust in level flight.  When an aircraft climbs, it needs more thrust.
The easiest way to understand this is to point the aircraft/rocket in a 90 degree (vertical) climb.  The wing no longer helps at all, and thrust alone must match gravity plus drag from forward motion.
A winged aircraft in level flight needs much less thrust because the wing is far more efficient at creating lift to counteract gravity.
As the aircraft raises the nose to climb, the lift vector tilts away from vertical.  Vertical lift is lost by cosine degrees climb.  A 10 degree climb loses only 1.5 % of the vertical lift but requires 17 % (sine 10 degrees) more thrust to compensate in addition to thrust required to maintain airspeed.
One can see thrust requirement will increase as angle of climb increases.
In order to be most efficient from the aerodynamic point of view, the aircraft raises its nose a bit further than the line of flight to maintain its best angle of attack.  This is done in level flight, climbing, or descending.

the difference is the amount of thrust required to maintain that straight line of flight and AoA in all cases

This answer seems rather over-complicated/confusing compared to what the OP is asking.

@MikeB please see this question.  Much has been written about this subject at this site.  Perhaps you would like to contribute an answer as well.

The Angle of Attack, which is roughly the delta between the fuselage and the velocity vector, is on the order of 5-10 degrees shortly after takeoff. This difference from exact alignment of the vector and the fuselage would be hard to observe from any single fixed point, with the aircraft moving past the observer pretty rapidly, but it is real - and very important to the flight of the aircraft!

I think the reference line of angle of attack is usually the chord of the airfoil, which is not necessarily parallel with the fuselage. The difference is angle of incidence.

@jpa  Yes, but as a matter of providing a conceptual answer to the posted question, that distinction doesn't really illuminate what's involved in the difference between deck angle & the flight path vector. At a more advanced level, then angle of incidence becomes an essential part of the discussion.

Or, 3rd option, is the airplane designed such that the lift of the wings in the default take off configuration results in a parallel flight, e.g. because this is most efficient from aerodynamic POV?

This is your best guess so far, but not exactly how I would describe the attitude.
Landing Configuration and High AOA
Remember, airplanes almost always use a different wing configuration for landing.  Along with the extra lift and drag provided by flaps, there is a change in angle of attack and a corresponding change in the required pitch angle.  Because the angle of attack needs to be on the high side to maintain a low speed, the fuselage doesn't point downward unless full flaps are used.  On some airplanes the full flap range is not needed or even detrimental to manuevering, so in a sense there's an advantage to flying more nose up rather than "parellel" to the flight path.
Relative Wind During Climbout and Low AOA
Relative wind is tilted down (from the upward direction) during a climb, so even with a low angle of attack, the pitch angle is above the horizon and still close to the flight path angle.  For turbojet aircraft, the climbout profile involves increasing airspeed and making configuration changes that influence the needed pitch angle.  You might observe slight pitch changes during the initial climb because the acceleration and changes of configuration are changing the angle of attack and changing the rate of climb.  Those happen even in stable weather.

I think that the following picture (source) summarises in a simple way what happens in a climb:

The airplane is moving along the red line labelled with "Flight Path" and having an inclination $\theta$ in respect to the horizon. The wing (and the fuselage it's attached to) is a bit more sloped than $\theta$ by an angle $\alpha$, which is the angle of attack that it needs to generate enough lift to win the ($cos\theta$ part of the)  weight. By definition, lift is perpendicular to the flight path and drag is parallel. The thrust generated by the engine(s) is normally aligned with the "Fuselage Reference" and it therefore has a (very small i.e. proportional to $sin\theta$) upward component. That's actually all.

In addition to the fine answers above, aircraft normally take off into wind and so the flight vector relative to the ground will be steeper than the vector relative to the air - in an extreme case an aircraft might ascend vertically if the wind speed equals takeoff speed.  Typically though the wind speed might be 10-15kts and with a takeoff speed of 100kts or so the aircraft would indeed appear to fly at zero angle of attack.

GREAT QUESTION! Really shows that you're trying to understand the concepts in depth. Here's my attempt to give a simplified explanation of aircraft performance.
One of the golden sayings in aviation is:

ATTITUDE + POWER = PERFORMANCE

One thing to keep in mind is that lift is produced due to the airflow over and under the wings. Thrust produced by the engine and the attitude (which is how far above or below the horizon the nose is pointing) work together to give us a certain amount of airspeed (which translates to the amount of airflow over and under the wings) which gives us the desired performance.
At any given phase in flight, we are trying to achieve an optimal combination of power and attitude (and also airspeed). A light single engine C-172, for eg., will use full throttle and adjust the pitch to get an airspeed of 75-80 kts (depending on the specific model of 172) to get the best rate of climb.
The reason why you see the fuselage parallel to the direction of travel during climb is because the the angle of attack required for an acceptable climb performance happens to be at the pitch at or very close to the direction of travel. In theory (at least), you "could" climb with the nose pointed higher than the line along which you're travelling but it wouldn't be very efficient, at least for most planes.
Similarly for approach and landing, we are trying to achieve an optimal combination of speed, thrust and flaps configuration, etc., to have a rate of descent and airspeed that is stable for that aircraft. When we fly slow, we generally use a lower power setting and so we have to compensate for the reduced lift by pitching up - which is why for bigger airplanes you see the nose pointing slightly above the horizon even while descending towards the runway as they have to pitch up that much to compensate for the lower thrust. The equilibrium you have to maintain to be along that travel path is what's important here. Any more thrust and the rate of descent will reduce and if you pitch down to compensate for the increased lift your airspeed willincrease. We try to balance the energy and have a stable configuration.

True, but when you are  landing , you decrease gradually the speed on final, that alone will increase the AOA, then aerobrake,flying parallel to the runaway, visually the nose is upward, but when you take off the speed "is alive", increasing,  the aircraft become" clean "landing gear up, flaps up, no needed for much of Angle of Attack. Also the parallax have a great role in view on this instance.

The question was about taking off...


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Does the order in which engines in commercial airliners are turned on matter?
I've seen videos on youtube where the pilots always turn on engines 4 and 3 (in a B747-4) first and then turn 2 and 1 on after pushback. Is there a reason behind this, and does the same reason apply to all multi-engine aircraft?

There's a lively debate about this, https://www.pprune.org/tech-log/415625-747-2-engine-start.html.  The consensus seems to be that starting one at a time is nicer to the APU, and starting some before pushback ends saves you precious seconds at a busy airport.

Welcome to aviation.SE! Does this question help? This one and this one might also be relevant.

Short answer is it depends on the airplane.


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What type of charts does Jeppesen FD Pro X use?
In Jeppesen FD Pro X application in EFB (iPad), What type of charts are being used in Approach plates and High IFR enroute charts ?
Provide the source, if possible.

The approach charts are the standard Jeppesen charts, while the enroute map isn't analogous to any paper chart, but rather depicts selected chart components such as navaids, airways, terrain, weather, etc.
Source: I've flown with Jepp FD Pro at work for about a decade, so personal experience.


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What are these 3 stages of twilight?
The extreme left is Day and Extreme Right is Night. In between are those Civil twilight, Nautical and Astronomical Twilight ?

There are mainly 3 stages of twilight. There are defined by how many degrees below the horizon, the sun is.

Astronomical twilight starts when the sun is at $-18^\circ$ altitude, before sunrise. It ends when the sun is again at $-18^\circ$ altitude, but after sunset.

Nautical twilight starts when the sun is at $-12^\circ$ altitude, before sunrise, and ends when the sun is again at $-12^\circ$ altitude, after sunset.

Civil twilight starts when the sun is at $-6^\circ$ altitude, before sunrise, and ends when the sun is again at $-6^\circ$ altitude after sunset.

Sunrise is when the sun is at $-0.22^\circ$ altitude ( same for sunset ).

Astronomical twilight is the darkest part of twilight. An overview of these stages of twilight is here:

Here, C is Civil Twilight, N is Nautical Twilight and A is Astronomical Twilight.
Even in flightradar24, extreme left is day, a little bit darker is Civil Twilight, a little bit darker than civil twilight is Nautical twilight, a little bit lighter than night is Astronomical twilight. Darkest part is night.

@Bianfable   Astronomical twilight ends when the sun is at $-18^\circ$ altitude. This means that astronomical twilight is between the times when the sun is $-12^\circ$ till when the sun is $-18^\circ$. Night starts after the sun is below $-18^\circ$ altitude (after astronomical twilight).
By terminators, do you mean twilight zones?

Sorry, I misread the answer, makes sense now! I never heard the term twilight zones before, I always use terminator, but according to Wikipedia they are the same thing. I'm still not sure if this is actually the definition used by FR24 though...

You can use both of them, but I usually use the term twilight. That's why I thought that was better than terminator (my personal opinion, you can use either).

Stages of twilight are defined by the angle of the center of the Sun below the horizon.

Astronomical twilight (the darkest) begins when the center of the Sun is 18 degrees below the horizon
Nautical twilight begins when the Sun 12 degrees below the horizon
Civil twilight begins when the Sun is 6 degrees below the horizon
Sunrise occurs when the center of the Sun is at the horizon, ie. half of the sun is above the horizon.

At sunset stages are of course reversed. Wikipedia has more:
https://en.wikipedia.org/wiki/Twilight#Definitions_by_geometry

Sunrise is not when the center of the Sun is on the horizon. Sunrise is when the upper limb becomes visible. See https://en.wikipedia.org/wiki/Sunrise. Also, the original question is whether flightradar24 is showing the three zones of twilight. Your answer is for a different question: what are the definitions of twilight.

As an aside, the FAA considers civil twilight to be day and the others night. https://aviation.stackexchange.com/q/33361/8730

You should probably mention "sunrise" before describing the angles; for someone thinking of sunset twilight there's confusion before realising what's meant


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Is the Special Traffic Management Program (STMP) still in use?
I'm doing some research on STMP.

this NBAA link say that STMP is gone.
however, this link makes it look like STMP was in use for oshkosh 2021. the subdomain may indicate it wasn't used though so it's just not clear.

My question/s:

is STMP dead?
if so, does anyone know when and why it ended?

i found some additional information about Oshkosh 2021. their NOTAM (page 25) specifies that IFR arrivals and departures must use e-STMP. so it is definitely still alive for certain airports when needed.


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Under which conditions is full rated power instead of METO power required for takeoff (DC-3/C-47 with Pratt&Whitney 1830 twin wasp engines)?
OK, so my explanation is going to be quite long, but please bear with me. My question is in two parts, but first I'll explain what I know.
I was reading the C-47 Pilot's Flight Operating Instructions and the DC-3 Organisation Control Manual, and they both say that takeoff should be performed at full-rated power.
This link shows a bunch of good reasons why one should always use maximum power for takeoff
[FAA mandatory for commercial operations; P&W endorse it;

'The distance the pistons travel in the cylinders (stroke) is related
  to the power used. The piston rings, over time, wear a ridge into the
  cylinder wall at the top and bottom of the stroke. If 42" is used for
  takeoff, the bottom ridge will develop further up the piston wall than
  in an engine that has seen rated power for Takeoff. If the time comes
  when full rated power is needed (short runway, engine failure, etc.)
  and a power setting greater than 42" is used, the piston is now forced
  past the ridge in the cylinder created by many hours of using de-rated
  power. Forcing the piston rings past this ridge can cause them to
  break'

;carburator has additional cooling feature past 45"; engines last longer],
but also mentions the fact that full-rated should only be used for one minute at a time (which is apparently one of the reasons some people choose to take off with METO power instead).
One minute sounds like a very short time to me (and to the person defending T/O with METO power), but I'm not a pilot, so I do not know how long a  normal T/O roll with a DC-3 at maximum takeoff power  would take.
The DC-3 performance information sheet (found here) mentions that (at sea level and normal runway conditions) a 1700 ft T/O roll is enough to reach 100 mph (which I am assuming is the minimum takeoff speed ), but it says nothing about how long  the DC-3 would take to reach that.
They also mention that at 5000 ft altitude it'd take a 2300 ft T/O roll to attain that same speed. But that still doesn't tell me how long that would take because I don't know the acceleration rate the DC-3 has. I've checked the charts, but I admit I couldn't conclude anything from them (doc is semi-readable, plus, it might have been way over my head anyway). I'm sorry if this question is stupid, maybe I need to brush off my physics , but I really am not managing to figure this one out on my own ...
I am aware there are a number of variables that come into play here, but I'd be happy if anyone could give me an approximation , or even an example of what conditions need to exist for the DC-3 to take only a minute to do the T/O roll (if one wanted to use full-rated power).
And, more importantly: Would a wet grass runway at an almost 6000 ft altitude airport, plus having the aircraft at maximum takeoff weight (or close to it) justify choosing to take off with METO instead of full-rated power? I mean, such a T/O roll would definitely take over a minute, right?
Thanks a lot

“The distance the pistons travel in the cylinders (stroke) is related to the power used.” What? That makes no sense. The piston is connected to the crankshaft by a solid rod, so it must always travel the same range during each complete revolution.

@ Jan - I quoted it from the link provided ipsis litteris. I felt tempted to edit that part out because I thought it was too long, but as I'm not a pilot or engineer I feared I'd  make a mistake, so I copied exactly what was written there). thanks

@ Jan - anyway, that part is not what really  mattered to me. I'm interested in valid reasons for taking off with METO power. Mainly the ones I asked about, but not restricted to those. The reason I added that info was to avoid getting answers that would tell me that no one should take off without full-rated speed (and then list those reasons). I took it from a website that seems to be trustworthy and the people that wrote that have been flying DC-3s for a long time... Thanks

Yes, I understand you quoted it as you got it. I am saying it does not sound right. And it's not like it was official documentation anyway. And I also understand it is not the actual question—that's why I wrote a comment, not an answer.

@ Jan - no , that wasn't in the official docs. One captain mentions it throughout the text and the one that is presumably in charge of the page also mentions it at the beginning , seemingly in agreement. Let me get his quote for you. give me a sec

'It has been found of late, that de-rated power takeoffs can cause the piston rings to break, because they create a ridge at each end of the cylinders end walls, thereby, when ever full power is needed such as a "single engine out emergency" problem may occur with engine cylinders caused by breakage of the piston rings. Incidentally, Pratt & Whitney endorse the use of full power contrary to there own report in 1953 advising to use de-rated power at the time.'  it's a different person speaking now  (quote from http://www.douglasdc3.com/dc3throt/dc3throt.htm )       thanks

@ Jan - the way he put it, "it has been found of late" , made me think it was a fact. I don't know better so it didn't cross my mind to dispute it. apologies for that. Do you reckon I should edit that part out to avoid changing the focus of the debate?

There is nothing to apologise for. And there is no need to change it; answers and comments are separate.

Ok, thank you for your help.

This is a really good question. Don't feel sorry for its length as it add a lot of precision and make the answers more specific

@ Manu H - thank you for that. I felt tempted to  delete this yesterday because I felt a bit daft. I appreciate the comment.

@JanHudec - reading through the linked page, I think there's some confusion. I initially thought the same thing you did - there's no way the piston stroke can change (and a 42" stroke sounds like a marine diesel, not an aviation engine)! I think the 42" refers to manifold pressure. I think that (maybe) increasing that MP to full power (48"?) can cause the piston to hit top/bottom harder? than normal causing the rings to fracture when they hit those ridges. Still not sure that's 100% accurate, but it's the only logical thing I can make of it. (con't...

... the 42 v 48" MP comes from the DC-3 Throttle's Management section of the link, while the cylinder ridge formation comes from point 1 under the Some differing opinions and interesting information: section. I've gotta admit - it explicitly says the piston stroke varies, and that's just mind-boggling to me...

Dang. There's an email contact link on that page, but the mailbox is full. I sent a question asking about this.

That part about piston travel is a misprint or just an error. It's piston velocity that increases as RPM increases in the engine. Piston velocity is a useful measure for determine the breaking point of an engine, as there are some pretty obvious limits to it.

Thank you all for the comments. As this is too hard for me to understand having no background in engineering or aviation, I won't comment any further. but  I'm also curious as to what they meant (as all of you are in agreement that it makes no sense) . Do let us know what they say if you can get that email to go through, please,  @FreeMan

@DeltaLima - thank you so much for helping out with the readability of this question. it looks a million times better. I don't know how to do that (the link to another page without showing the actual address and the indented quotation). Would you mind sending me a link that explains how to do that? I had a hard enough time trying to add a picture to another SE lol . thanks a lot

@DeltaLima - I went into "edit mode" and saw what you did. I think I understood it. Putting it to test now. Thank you so much for that

Steel is elastic, isn't it?  A piston rod must see quite a bit of tension when decelerating the piston.  It's not inconceivable to me that there's enough force to stretch the rod a little, with higher RPMs causing more tension and therefore more stretch.  What I don't know is how much stretch--could it be enough to account for the advice the OP is asking about.

Let's consider your case of a 2300 ft (700 m) takeoff roll. Your link lists the procedure as reducing power upon reaching 90 kt (46 m/s). To make things easier we can assume constant acceleration. That won't be true in real life but it will give us an approximation.
Two basic equations for acceleration, relating distance $s$, acceleration $a$, time $t$, and velocity $v$:
$s=\frac{1}{2}at^2$
$a=\frac{\Delta v}{t}$
Substituting our known values in, we get:
$700\ \mathrm m=\frac{1}{2}at^2$
$a=\frac{46\ \mathrm{m/s}}{t}$
Soving for $t$, we get about 30 seconds (and $a=1.5\ \mathrm{m/s^2}$). Even accounting for acceleration reducing as speed increases, that suggests there's plenty of room to reach 90 knots in less than one minute.
If we look at what takeoff roll would result if we need 60 seconds to reach 90 knots, we get 1380 m, or 4500 ft.
To verify this you can also look up videos of DC-3 takeoffs. Like this one, which seems to take about 30 seconds:

I agree with the comments, piston travel changing significantly with power setting does not make sense.

Thank you @fooot for taking the time to help me with this conundrum. I apologise for my unintentionally  (mis)leading you to think both pieces of  info came from the same link. I've added the second link now to correct that. But it should still make sense given that both links talk about the same machine, right?    Thanks a lot

Thank you so much for your help. I'd have never figured this out on my own. I didn't think of using two equations to substitute the missing variable and didn't realise it'd be ok to assume constant acceleration, so I'd have never come to that conclusion myself. So 60s doesn't seem that little after all, even at 5000ft altitude, and apparently the weight (according to the second link) doesn't account for that much difference either. So would the wet grass runway (in my example) account for the only reason to use METO for T/O ? thanks a lot

And how much do you guys reckon the heat would affect that (the first link says "heat gives the 5,000 ft ASL field a density altitude of 8,000 ft") ? Would I calculate the length of the T/O roll as if the altitude of the airport were actually 8,000 ft? Would any of you disagree that the weight makes little difference (second link says so, but I saw a number of links that attributed longer takeoff rolls to the aircraft being fully loaded and thus very heavy)?

Both heat and a grass runway would reduce the acceleration, it's hard to read the performance document but I didn't see any hints about how much difference those factors would make.

Yeah, I agree it's not the best copy. Sorry about that. I didn't see any mention of that either (in any of the DC-3 docs I found). the only variable the "take-off" text mentions (second link)  is the  altitude of the airport . and it also says changes in gross weight would not be very noticeable at sea level ...  Am I to assume that they'd make a difference at higher altitudes? Thanks a lot

Yeah, as altitude increases, takeoff distance gets longer, and differences like weight start to be more noticeable. You can see in the takeoff runway required chart, at sea level the lowest two weights differ by 500 feet length, at 6000 feet they differ by 1000.

I was not able to make sense of the charts,  and the one I thought mattered the most was  scarcely readable to me, but perhaps that was because I wasn't sure what I was looking for (I couldn't wrap my head around the concepts that this matter entailed until you explained them to me) . I will take another look. Thanks again for your help

Connecting rods stretch/rod caps oval at high rpm. .030" is a common assumption for automotive engines with forged steel rods.
I've always heard it discussed (again, in auto engines) as solely an rpm function rather than a power setting function. But the document cited does make a point of discussing the bottom ring land, which makes sense if you're dealing with an effect of power rather than rpm. Whereas auto excursions related to rpm are more about the top ring land because most of the flex is in caps/cap bolts, which is all stretch/ minimal compression.


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Would it be feasible to build a jet fighter plane based on a wooden construction?
I read about the de Havilland Mosquito recently and that it was a quite successful British bomber in WW2 due its lightweight wooden construction. As far as I understand it, usual planes at that time were built mainly with metal parts already, thus heavier than the Mosquito and hence uncatchable for them. Furthermore it was too fast for getting hit by heavy anti air, namely the German 88mm cannon.
With this traits of a wooden construction, I wonder if it is feasible to build jets mainly of wood and give them a boost in speed. I have doubts however that the wooden construction is stable enough for resisting the hefty g-force mid-air while flying in mach 3 speed.

Even metal jets don't spend a lot of time at Mach 3.

@SteveV. True, but the ones that do have to be able to take the loads, nonetheless. Granted, I don't think any fighters actually fly at Mach 3, do they? The SR-71 did, though.

The weight difference wasn't really that big. In the end what matters is the lift-to-drag and thrust-to-weight ratios and Mosquito was simply all around well designed, which at the time, with no computer modelling, still required good deal of luck, and had powerful engines. The main advantages of wood were in resources—metal was in high demand and so were workers skilled with it while wood and wood workers were available.

Perhaps someone like Jan or Peter who knows a lot more about supersonic aircraft design than I do can construct an answer, but I'd suspect that compression heating would also become a big problem with a wooden frame for aircraft in the Mach 3 range. The SR-71 had skin temperatures from 230 C up to 500+ C. Many woods ignite between 300 and 350 C.

Acceleration (during turns, climbs, etc) is a much bigger issue than speed.

@reirab MiG-25 and MiG-31 seem to be able to reach Mach 3+

You question is unclear.  Do you mean now, in the 21st century, or at some point in history?  Unless you clear that up, your question is too vague.  As to the 88, any plane hit by that, wooden or no, was going to have a bad day.

The sr71 was not a fighter tho

G force and speed aren't at all the same, and not really related.  I doubt that for instance the Concorde ever experienced significant G force, while many small aerobatic planes do.  Some of those, like IIRC the Pitts, have at least partly wood construction.  With G force, the real limitation is the pilot, not the construction material.  Though at higher Mach numbers, you might have to worry about a wooden plane catching fire from air friction :-)

Yes it would be possible to build a fighter plane from wood, not one that can fly at Mach 3 however. There are some olden days examples of fighter planes using wood construction, here is another one from 1938: the Fokker G.1. with a wooden wing. These planes don't look like F16s, but were subject to fully aerobatic g-forces.

This document of 1941 provides an overview of knowledge of aeronautical wood construction. Wood is a light construction material, and one of the largest aircraft ever built, the Spruce Goose, was made entirely of wood. Wood also has asymmetrical strength properties: it is much stronger in line with the grain than perpendicular to it, one of the main advantages cited for composites. We could follow the same construction method as for composites: shave off thin layers of wood and embed them in resin, line up the majority of the grain in the direction of greatest stress, and use some alternate grain directions like in plywood to create sufficient strength and stiffness in all directions.
If we consider the properties of aeroplane construction materials:

Strength.
Wood has a specific strength that is slightly lower than that of aluminium: spruce has a compression strength of 27.5 N/mm$^2$ = 27.5 MPa, and a density of 418 kg/m$^3$. Compare this with untempered 7075 aluminium alloy: a tensile strength of 280 MPa and a density of 2,810 kg/m$^3$. Aircraft aluminium alloy is 10.2 times as strong and 6.7 times as heavy as spruce, so its specific strength is 10.2/6.7 = 1.52 that of spruce. But half of the wing is compression loaded, and a thicker skin made of a lighter material buckles less easily. So for wings with a high aspect ratio, part of aluminium's weight advantage is traded in: compressed skin is dimensioned on skin thickness, not on yield strength.
Heat resistance/flammability
Aircraft aluminium alloys yield strength reduces as a function of temperature, as indicated in the graph below (source). The red line is for 2024 aluminium: at 250 °C, the tensile strength (= compression strength) is halved.

Compare this with the compression strength of spruce: halved at around 150 °C (Source: fig 5-14 of the Wood Handbook). There are two graph regions for different moisture contents, and that brings us to the main disadvantage of wood: the variability of a natural material, next under point 3.

But of course the main point of attention would be using a jet engine in a wooden frame. Even the G.1 had an aluminium front engine construction.
Consistency and weather resistance
From AIRCRAFT WOODS: Their Properties, Selection, and Characteristics

...the principal factors tending to restrict the use of wood are a not unlimited supply of the most desirable species; a hygroscopicity that results in shrinking and swelling and changes in strength; and a wide difference in properties with different directions of the grain.

These disadvantages can be partially undone by using plywood, however this has an additional weight penalty.

Wood has not been used for several decades for constructing airliners or fighters, and for a good reason. Fokker successfully built wooden monoplane aircraft in the 1920/1930s, until a high visibility crash of an F.X brought this construction method under scrutiny. Not long after, the Boeing 247 and the DC-2 pioneered aluminium smooth skin aeroplane construction, and the industry has never looked back.
So yes, a fighter can be built out of wood and would be strong enough. However it would be heavier, prone to weather influences, and cause of major headaches for integrating a jet engine into its flammable construction. It cannot fly at Mach 3: the SR-71 needed to be built out of titanium, not aluminium, due to the heat resistance required. Spruce would not stand a chance and go up in flames.
There are no good reasons to not build a fighter jet from metal or nowadays composits.

@pericynthion indeed.

@pericynthion You clipped that sentence short. The "nowadays composits" would cover the stealthy part. And would probably do a better job than most other materials. And considering the massive brain-power that has gone into modern stealth aircraft, I think Koyovis' final statement is valid.

Yes indeed, @pericynthion made a good point.

Apologies to @pericynthion then. Didn't mean to be as harsh as I sounded. Though I still agree with your last sentence, Koyovis. Wooden airplanes were pretty awesome in their days, but that time has passed. And I'm sure a future generation will look at our modern aircraft and have this exact same discussion about why you'd use metal and composites to build planes with. :-)

Please note that the answer is valid in general, but comparing compressile strength and tensile strength does not make much sense. It's like saying a subwoofer of 50W makes less EM emissions than a telco antenna of 500W: correct, but nonsense.

@EarlGrey. Oh yeah sure, buckling does not exist, right?

@Koyovis absolutely, you correctly mention "compressed skin is dimensioned on skin thickness, not on yield strength", but there are some steps in between the values you provide and that (correct) conclusion.

The wings and a few parts of the body of the Heinkel He 162 jet fighter were made of plywood.
https://de.wikipedia.org/wiki/Heinkel_He_162#Konstruktion_und_Ausr.C3.BCstung
The Bachem Ba 349 'Natter', a rocket-powered interceptor, was built almost entirely of wood.  https://en.wikipedia.org/wiki/Bachem_Ba_349

The Mosquito was not too fast to be hit by AA fire from 8,8 Flak (no aircraft is), but flew too high when operating near its maximum operational ceiling. The larger caliber 10,5 and 12,8 guns would reach higher but were not as widespread. With its maximum ceiling of 14.8 km, the 12,8 could easily shoot down a Mosquito.
Ed Swearingen once remarked that, regardless of what material you use, a design would turn about equal in weight. This is certainly true for GA aircraft if you compare wood, aluminium and composites. For a military aircraft, wood would have the biggest disadvantage because it is sensitive to water and will rot if it is not kept dry. If you can live with that, a subsonic wooden jet is easy to design.
In 1944 the wings of the Messerschmitt 109 were re-designed for wooden construction and the result turned out to be equivalent to the aluminium original, but a little heavier. Their main disadvantage, however, was that the wooden wings needed more working hours to complete. That the wooden rudder used in later variants was heavier than the aluminium rudder it replaced was mainly due to the enlarged size which improved directional stability at high speed.
Oh, and there are plans (and a few flying samples) of an all-wooden Me-109.
However, a pure wooden structure would be very hard if not impossible: Structural parts with high point loads (like the landing gear attachment or the engine mounts) could not be made of wood, but will need metal reinforcement. Like the engine, the landing gear itself would need to be made from steel. But the fuselage skin and wing surfaces could easily be wooden.
In fact, there was already a wooden jet fighter. The Horten IX (or Gotha 229) had wooden wings and a steel tubing frame in the mid wing with wooden skin. The skin would use a special type of plywood, called "Formholz", the layers of which were glued together in a mold so they came together with the right shape and curvature. Wood was chosen both to make the plane less visible to radar and as a non-strategic material.
I expect, however, that the designers would have selected a full metal construction had those limitations not existed.
If you want your jet to reach supersonic speed, I would definitely prefer to build large parts of it, like the wing's leading edge or the region around the afterburner, from metal. Wood could best be used if it is heavily filled with epoxy resin and not really pure wood anymore.

Wood is definitely lighter than metals, but it is not as strong. One important figure of merit here is the strength to weight ratio, i.e. the tensile strength divided by the density. Wikipedia lists strength to weigh ratios of various materials.  Let's compare just oak and 7075 aluminum.  Aluminum weighs about 4 times as much as oak, but is about 5 times as strong. So to take a given load, you need less aluminum (by mass) than you do oak.  That is why wood is not used in any aerospace construction.  Also note on this table how much higher carbon fiber composite is than aluminum.  That's a big driver behind why aerospace companies are moving to that material (e.g. the Boeing 787).

"I wonder if it is feasible to built jets mainly of wood an give them a boost in speed."  I have addressed the second part of the sentence: A wooden jet would be slower than an aluminum jet because it would need to be heavier because of the lower specific strength.

Note, however, that while aluminium 7075 is clearly better than oak, it was only developed in 1943 in Japan, so not available to British at the time of construction of the Mosquito. And the 6061 alloy, which was available at the time, is listed as on par with oak.

"Wood is not used in any aerospace construction" is a misleadingly overbroad statement.  It has been primary structure for many aircraft, is still a popular propeller material, and has been used as ablation material/skids for spacecraft.

“Wood is definitely lighter than metals” – lithium has a density of 0.53 g/cm³, lignum vitæ 1.23 g/cm³. (Granted, these are the extremes; for all woods and metals that are actually useful for aircraft construction, the statement is true.)

@ErinAnne, what about "wood is not currently used in modern aircraft structures"?

Tensile strength is only half the issue, though. Note that wood has very poor compressive strength because of its fibrous nature.

Another issue is that wood grows naturally, so it has possible hidden defects, which means you need to increase your safety margins (more weight).

@DanielKiracofe it might depend on how you define modern, given examples in other answers.  More to the point, I think it's tangential to the questioner's question.  There are good reasons to use metallic or composite construction in aircraft, but wood is definitely a suitable material even today, depending on your circumstances (say, for example, you already do a lot of woodworking).  As other answers show, wood is also suitable for jets in various amounts (though they won't be 100% wood, they may be as wooden as the Mosquito was).

It is probably misleading to look at Oak. Wasn't the Mosquito largely made from birch-plywood with a balsa core and "aircraft grade" spruce? It was quite a complex composite material.

The wiki article lists 7075-T6, which is heat treated. It will lose a lot of its strength when rewarmed by flying supersonic.

Engineered wood products like application-specific plywood can have much better strength-to-weight (and in particular stiff-to-weight, which is very important) ratios that bulk wood.  Oak is a heavy example (balsa is much lighter but only a little weaker -- from the linked table)

The Vampire - De Havilland again, and not long after the Mosquito (though too late for active service in WW2) - was partly of wooden construction. Like the Mosquito, being developed under wartime conditions (first flight in 1943) was no doubt one reason why.
Unlike the Heinkel 162 its development wasn't an act of desperation but a serious fighter that remained in service for 20 years with the RAF, and apparently until the 1990s as a jet trainer in Switzerland.
So, definitely possible, at least in the subsonic era, though the latter page says it was the last time wood/metal composite construction was used in high performance military aircraft (presumably counting the derivative Venom and Sea Venom as part of the same basic design)
Photos here quite clearly show the woodwork.

The Vampire was just used as a jet trainer in Switzerland until the 1990s (in two-seat form); they stopped being used as fighters in the 70s.

The answer is contained in your question and further implied although sometimes rather obliquely in some of the comments and answers.
The wooden de Havilland Mosquito used two Rolls Royce "Merlin" engines, with the exhaust stacks angled backwards because about the time of the development of that order of engine with that amount of power, it had been discovered that angling the exhaust stacks rearward gave a speed advantage in the low tens of miles per hour over the top speed of a 300mph-plus aircraft compared to when it did not have the stacks angled rearward. ie. there was something of a "jet" component already in the Mosquito with large quantites of hot air from powerful engines blasting backwards at full throttle.
EDITED: REFERENCE ADDED:
The below references about the "jet" effect I mention above, are not the two historical references I first discovered in 2010, which first led me to respond to the question. I have mislaid those references in house moves and computer changes.  I have not read the below references but it is all I could find now, probably given that jet effects from piston engine exhausts are rather irrelevant, and doubtless gradually becoming of even less interest, in modern aviation whether in war or peace time.
https://en.wikipedia.org/wiki/Rolls-Royce_Merlin
Scroll down to "Ejector Exhausts".  Note citations no.35 & 36.
cit.35: Price 1982. p. 51 (Bib: Price, Alfred. The Spitfire Story. London: Jane's Publishing Company Ltd., 1982. ISBN 0-86720-624-1).
cit.36: Tanner 1981, A.P.1565E, Vol.1, Section II  (Bib:Tanner, John. The Spitfire V Manual (AP1565E reprint). London: Arms and Armour Press, 1981.
ISBN 0-85368-420-0).
(end of the references edit)
Therefore I can't see much difference with pulling the Merlins out of a standard Mosquito and replacing them with gas turbines.  And there is my answer to the first part of your question.
Obviously the presence of scorching hot exhaust gases from two piston engines providing that "extra" thrust didn't bother the wooden Mosquito.
Of course, one would need to consider exact mounting position for turbine engines on a Mosquito as they spew out a lot more, and hotter, gas than piston engines, but I don't see that as an insurmountable problem.
And how "hot" is hot?  Was it the Canberra jet, a metal twin engined aircraft, which had the jet engines on the wings?  I never read anything about, for example, the paint on any logos painted on the sides of that aircraft being scorched or melted off by jet exhaust.  I suggest therefore, that even with the aviation understanding of the 1940s, that the Mosquito could stand as an example of a wooden jet aircraft that wasn't built, but could have been if the engines had been available.
And no, I am not suggesting the Mosquito would be capable of supersonic speed as a twin-jet.  That issue has already been addressed in comments and answers.
VAMPIRE BRIEF EDIT:
The WWII-developed de Havilland Vampire was of course part-wood construction.  It was used as the Royal New Zealand Air Force's fighter force for perhaps 20 years. The evidence of successful overall design was strong by dint of my personal observation of the aircraft screaming over my house for decades from the Ohakea AFB some 30 miles away. It's a moot point how much the wood contributed to the Vampire's success as a fighter, but it must contribute to part of the body of evidence that wood and jets can work together, even if only partially and at subsonic speeds.

Your answer does not provide any quantification, only assumptions. How does the gas mass flow and temperature compare of 1. A turbo piston engine that extracts the majority of fuel chemical energy to drive a crankshaft, and 2. A pure jet engine that converts all chemical energy of the fuel into a hot gas stream?

The Merlin puts given stress on the airframe at given speed both by reaction of major prop. blast and help from rearward stacks. A turbine can be chosen which burns fuel at a similar rate, with allowances for the different thermal efficiency so it puts a similar stress on the air frame at a similar speed. Even with the differences in thermal efficiencies between the engines, we are not talking of an entire order of magnitude difference in the "fuel chemical energy" even though the basic Gas Laws result in a "cooler" exhaust from the piston engine.  So it's "feasible", as the question did ask.

Koyovis, I re-read your answer to this question, and I do take your point about my assumptions, thank you.  You couldn't know of my 4 yrs engineering, physics & metallurgy studies at college level, which possibly might have changed my "assumptions" to "informed opinion" in your eyes.  I chose the concept of putting jet engines on the Mosquito, capable of close to 400mph with piston engines & more manoeuverable than most else at the time. I would suggest therefore, an ideal "test frame" for the "feasability study" alluded to in the question. Sorry, felt I had to reveal some humble credentials

Pleased to make your acquaintance. You can find the quantifications that back up my own statements in my answer. In your answer, the bit about the exhaust pointed backwards resulting in a higher speed is interesting, and it would be even more so if there would be a reference. Opinions are not upvoted on this site.

I am a "newby" here but I assume I can come back in, say, a week or so and put some references about the exhaust stacks in a comment here?  I did come across one concerning the Hurricane, and another to do with the P51 Mustang stating the angled stacks were angled for "jet" assist. Neither reference claimed big speed advantages for doing that, just a way to tweak the speed up a little. Both references referred to the jet effect.  Neither even mentioned a possible "extractor" effect which might be caused by angled stacks having a low pressure area behind them at speed.  I'll go looking.

Yes you can edit the answer any time, by using the "edit" link underneath it. Welcome to the site.

Answer edited with refs.  My extra edit about Vampires could be seen as "opinion" and thus declared not valid, but I argue that empirical evidence is widely accepted across many disciplines, and one of the accepted criteria of empirical evidence is being able to repeatably observe identical results from identical "experiments".  I saw the Vampires being flown over thousands of repeated "experiments" of their ability to fly reliably.  The only "failure" to fly was reported in all major new Zealand newspapers, c.mid-1950s, when two Vampires collided in mid-air. One pilot bailed out, survived.

@Koyovis  still learning how to work this site.  Just found out what the "@" symbol does.  References about jet exhaust stacks now in my answer. And pleased to see they more credible than the 2 I had mislaid. Cheers

A bomber? Yes, but FYI, the Mosquito was a fighter-bomber and was used extensively as a night-fighter.
Previous answers have pointed out - correctly - that high-performance subsonic aircraft have been constructed using wood.
I say 'using' because even the Mosquito used some steel and aluminium - but the wing spars, the skin, and the structure of the fuselage were wood, and that's a reasonable definition of 'made from wood'.
Wood's a good composite material, when used with care - but it's variable, and both the manufacturer and maintenance team need to use skill and judgement to use it effectively. And that's the point: as aircraft design pushes further at the limits of the materials, the safety margins are reduced - but safety is maintained within those tighter margins by precise stress analysis at the design stage, rigorous quality control in manufacturing, and repeated inspection in service.
You can do this with the consistent materials we manufacture from metal, and (nowadays) from carbon and Kevlar composites - and composites were dogged by the same problems of consistency that bedevil wooden components until the last 10-15 years.
It's not that they, or wood, were weaker at a given cost and weight - in some cases, they are stronger - the issue is that they didn't deliver the performance consistently and therefore couldn't be used without widening the safety margins - extra weight - and an uneconomical excess of effort in quality control and in-service inspection.
Moving to the supersonic flight regime, it's all much more demanding. The wings have to be much thinner - chord ratio less than five percent - so both the spars and the skin have to be thinner and that's pushing the envelope too far to do it safely with wood. Note also, that the friction forces are higher - massively so in some areas - as are the positive and negative pressure loadings on the skin during the transition between sub- and supersonic flight.
This is especially true of the control surfaces.
It is theoretically possible to do it, with some metal in critical areas and serious epoxy injection, but you'd be getting close to making the wing out of solid wood and you wouldn't do it for the tailplane at all. The weight penalty would've been a no-fly for the first-generation supersonic aircraft and, while more powerful engines make that less of an issue today, the cost in range and payload is unacceptable.
Also, it would glide like a sawn log and that's got implications for safe landing speeds as well as safely landing 'deadstick' with an engine failure.
As a final note, the Mosquito was surpassed by the Hornet in 1944/45 - too late for WW2 and a hundred knots slower than the Gloster Meteor. I mention this because the Hornet was, in broad terms, the 'Wooden Wonder' re-engineered in aluminium: similar size, similar planform, same engines. While the Mosquito was good, it's nowhere near Winkle Brown's "The excess of power was such that manoeuvres in the vertical plane can only be described as rocket-like" that he and other pilots experienced in its metal successor.
And that's your answer: you can build high-performance aircraft out of wood, but you'll always be able to build a better aircraft out of aluminium and steel.

The Hornet was scaled down from the Mosquito and (as a single seater) used a much smaller fuselage. With a more powerful, later version of the Merlin engines it is no wonder that performance was spectacular.

Welcome to the site, +1 for a well  presented first answer.

Do not forget the material shortage during world war 2 which required intelligent methods of equipment construction with materials which were readily available i.e wood.
I would think that the higher performance of todays aircraft would be a significant factor when it came to maintenance. Wood vs metal alloy in a higher stress environment would require more maintenance.
If you look at airfields today, I have found all wood frame and canvas aircraft sitting in hangers overnight where as spam cans are left outside in all weather.

Yes, a jet fighter made primarily of wood is possible.It has been done!
https://en.m.wikipedia.org/wiki/Heinkel_He_162

According to an article by Reimar Horten in the Argentinian National Aeronautics magazine, in 1936, the German company Farben Werke (Color Works) had build an all-plastic, supersonic flying wing prototype, to be powered by a turbine engine.
 Would the De Havilland Mosquito have flown supersonic with its Balsa Wood parts if adequately shaped and powered? Why not?


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How can I calculate stall speed using foilsim?
I need to find the stall speed of an airfoil using foilsim not the formula (https://www.grc.nasa.gov/WWW/K-12/airplane/foil3.html)

Hi Jona, welcome to Aviation SE. You might want to add a link to Foilsim. This is Java software written by NASA for running in a browser.

All you can do with any airfoil analysis software is to calculate the stall angle of attack and lift coefficient. To get to the stall speed, you need to have knowledge about the wing loading and wing shape of the particular aircraft you need to calculate the stall speed of. For a single airfoil no stall speed can be defined - this is only possible for a specific airfoil on a specific airplane.
Foilsim allows you to add this information via the "size" button. Next, click on the "shape" button and increase the angle to the maximum where the flow on the upper side does not yet separate from the airfoil contour. If you now change to the "Flight" button, you can enter the speed and altitude. Select "Lift" on the right side and see how the lift changes with speed.
If you divide the lift by the gravitational acceleration of the selected planet (yes, you can run Foilsim on Venus or Mars, too - on earth that would be 9.806 m/s²), you get the mass of the aircraft that will stall at the selected speed.
However, since this is a very simple simulation that is not meant for actual aircraft design, and the airfoil shape cannot really be selected beyond camber and angle of attack, I advise you to not build an aircraft with those results. The fact that the stall angle of attack is always 10°, regardless of the airfoil contour used, should be warning enough.